The member of this family from Treponema pallidum differs in having three rather than just one copy of the BRCT (BRCA1 C Terminus) domain (pfam00533) at the C-terminus. It is included in the seed. Length = 652

DNA ligases catalyze the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilizing either ATP or NAD(+) as a cofactor, but using the same basic reaction mechanism. The enzyme reacts with the cofactor to form a phosphoamide-linked AMP with the amino group of a conserved Lysine in the KXDG motif, and subsequently transfers it to the DNA substrate to yield adenylated DNA. This alignment contains members of the NAD+ dependent subfamily only.. Length = 307

DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor. This domain is the catalytic adenylation domain. The NAD+ group is covalently attached to this domain at the lysine in the KXDG motif of this domain. This enzyme- adenylate intermediate is an important feature of the proposed catalytic mechanism. Length = 315

DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor. This family is a small domain found after the adenylation domain pfam01653 in NAD dependent ligases. OB-fold domains generally are involved in nucleic acid binding. Length = 82

The BRCT domain is found predominantly in proteins involved in cell cycle checkpoint functions responsive to DNA damage. The BRCT domain of XRCC1 forms a homodimer in the crystal structure. This suggests that pairs of BRCT domains associate as homo- or heterodimers. BRCT domains are often found as tandem-repeat pairs. Structures of the BRCA1 BRCT domains revealed a basis for a widely utilized head-to-tail BRCT-BRCT oligomerisation mode. This conserved tandem BRCT architecture facilitates formation of the canonical BRCT phospho-peptide interaction cleft at a groove between the BRCT domains. Disease associated missense and nonsense mutations in the BRCA1 BRCT domains disrupt peptide binding by directly occluding this peptide binding groove, or by disrupting key conserved BRCT core folding determinants. Length = 77

It is active during DNA replication, DNA repair and DNA recombination. There are two forms of DNA ligase: one requires ATP (6.5.1.1 from EC), the other NAD (6.5.1.2 from EC). This family is predominantly composed of NAD-dependent bacterial DNA ligases. They are proteins of about 75 to 85 Kd whose sequence is well conserved , . They also show similarity to yicF, an Escherichia coli hypothetical protein of 63 Kd.; GO: 0003911 DNA ligase (NAD+) activity, 0006260 DNA replication, 0006281 DNA repair.

DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor. This domain is the catalytic adenylation domain. The NAD+ group is covalently attached to this domain at the lysine in the KXDG motif of this domain. This enzyme- adenylate intermediate is an important feature of the proposed catalytic mechanism.

DNA ligases catalyze the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilizing either ATP or NAD(+) as a cofactor, but using the same basic reaction mechanism. The enzyme reacts with the cofactor to form a phosphoamide-linked AMP with the amino group of a conserved Lysine in the KXDG motif, and subsequently transfers it to the DNA substrate to yield adenylated DNA. This alignment contains members of the NAD+ dependent subfamily only.

DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor. This family is a small domain found after the adenylation domain pfam01653 in NAD dependent ligases. OB-fold domains generally are involved in nucleic acid binding.

The BRCT domain is found predominantly in proteins involved in cell cycle checkpoint functions responsive to DNA damage. The BRCT domain of XRCC1 forms a homodimer in the crystal structure. This suggests that pairs of BRCT domains associate as homo- or heterodimers. BRCT domains are often found as tandem-repeat pairs. Structures of the BRCA1 BRCT domains revealed a basis for a widely utilized head-to-tail BRCT-BRCT oligomerisation mode. This conserved tandem BRCT architecture facilitates formation of the canonical BRCT phospho-peptide interaction cleft at a groove between the BRCT domains. Disease associated missense and nonsense mutations in the BRCA1 BRCT domains disrupt peptide binding by directly occluding this peptide binding groove, or by disrupting key conserved BRCT core folding determinants.

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriophages, eukarya, archaea and bacteria. Some organisms express a variety of different ligases which appear to be targeted to a specific function. ATP dependent DNA ligases have a highly modular architecture consisting of a unique arrangement of two or more discrete domains including a DNA-binding domain, an adenylation (nucleotidyltransferase (NTase)) domain, and an oligonucleotide/oligosaccharide binding (OB)-fold domain. The adenylation domain binds ATP and contains many of the active-sit

>cd07906 Adenylation_DNA_ligase_LigD The Adenylation domain of Mycobacterium tuberculosis LigD-like ATP-dependent DNA ligases is a component of the catalytic core unit

Bacterial DNA ligases are divided into two broad classes: NAD-dependent and ATP-dependent. All bacterial species have a NAD-dependent DNA ligase (LigA). Some bacterial genomes contain multiple genes for DNA ligases that are predicted to use ATP as their cofactor, including Mycobacterium tuberculosis LigB, LigC, and LigD. This group is composed of ATP-dependent DNA ligases similar to Mycobacterium tuberculosis LigC. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. Members of this group contain adenylation and C-terminal oligouncleotide/oligosaccharide binding (OB)-fold dom

>cd07903 Adenylation_DNA_ligase_IV The Adenylation domain of DNA Ligase IV is a component of the catalytic core unit

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriohages, eukarya, archaea and bacteria. There are three classes of ATP-dependent DNA ligase in eukaryotic cells (I, III and IV). DNA ligase IV is required for DNA non-homologous end joining pathways, including recombination of the V(D)J immunoglobulin gene segments in cells of the mammalian immune system. DNA ligase IV is stabilized by forming a complex with XRCC4, a nuclear phosphoprotein, which is phosphorylated by DNA-dependent protein kinase. DNA ligases have a highly modular architecture consist

Bacterial DNA ligases are divided into two broad classes: NAD-dependent and ATP-dependent. All bacterial species have a NAD-dependent DNA ligase (LigA). Some bacterial genomes contain multiple genes for DNA ligases that are predicted to use ATP as their cofactor, including Mycobacterium tuberculosis LigB, LigC, and LigD. This group is composed of predicted bacterial ATP-dependent DNA ligases. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. The adenylation and C-terminal oligouncleotide/oligosaccharide binding (OB)-fold domains comprise a catalytic core unit that is common to most members of the ATP-dependent DNA ligase family, including this group. The adenyl

The mitochondrial DNA of parasitic protozoan is highly unusual. It is termed the kinetoplast DNA (kDNA) and consists of circular DNA molecules (maxicircles) and several thousand smaller circular molecules (minicircles). This group is composed of kDNA ligase, Chlorella virus DNA ligase, and similar proteins. kDNA ligase and Chlorella virus DNA ligase are the smallest known ATP-dependent ligases. They are involved in DNA replication or repair. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. They have a highly modular architecture consisting of a unique arrangement of two or more discrete domains. The adenylation and the C-terminal oligouncleotide/olig

>cd06846 Adenylation_DNA_ligase_family The Adenylation domain of proteins from the ATP-dependent polynucleotide ligase family is the minimal catalytic unit that is common to all family members

ATP-dependent polynucleotide ligases catalyze the phosphodiester bond formation of nicked nucleic acid substrates using ATP as a cofactor in a three step reaction mechanism. This family includes ATP-dependent DNA and RNA ligases. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP dependent DNA ligases have a highly modular architecture, consisting of a unique arrangement of two or more discrete domains, including a DNA-binding domain, an adenylation or nucleotidyltransferase (NTase) domain, and an oligonucleotide/oligosaccharide binding (OB)-fold domain. The adenylation domain binds ATP and contains many active site residues. Together with the C-terminal OB-fold domain, it comprises a catalytic core unit that is common to most members of the A

>cd07897 Adenylation_DNA_ligase_Bac1 The Adenylation domain of putative bacterial ATP-dependent DNA ligases is inferred by similarity to be a component of the catalytic core unit

Bacterial DNA ligases are divided into two broad classes: NAD-dependent and ATP-dependent. All bacterial species have a NAD-dependent DNA ligase (LigA). Some bacterial genomes contain multiple genes for DNA ligases that are predicted to use ATP as their cofactor, including Mycobacterium tuberculosis LigB, LigC, and LigD. This group is composed of predicted bacterial ATP-dependent DNA ligases. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. The adenylation and C-terminal oligouncleotide/oligosaccharide binding (OB)-fold domains comprise a catalytic core unit that is common to most members of the ATP-dependent DNA ligase family, including this group. The adenyl

>cd07905 Adenylation_DNA_ligase_LigC The Adenylation domain of Mycobacterium tuberculosis LigC-like ATP-dependent DNA ligases is a component of the catalytic core unit

Bacterial DNA ligases are divided into two broad classes: NAD-dependent and ATP-dependent. All bacterial species have a NAD-dependent DNA ligase (LigA). Some bacterial genomes contain multiple genes for DNA ligases that are predicted to use ATP as their cofactor, including Mycobacterium tuberculosis LigB, LigC, and LigD. This group is composed of ATP-dependent DNA ligases similar to Mycobacterium tuberculosis LigC. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. Members of this group contain adenylation and C-terminal oligouncleotide/oligosaccharide binding (OB)-fold dom

>TIGR02776 NHEJ_ligase_prk DNA ligase D; InterPro: IPR014143 Members of this entry are DNA ligases involved in the repair of DNA double-stranded breaks by non-homologous end joining (NheJ)

The system of the bacterial Ku protein (IPR009187 from INTERPRO) plus this DNA ligase is seen in about 200f bacterial genomes to date and at least one archaeon (Archeoglobus fulgidus). This entry describes a central and C-terminal domain. These two domains may be permuted, as in genus Mycobacterium, or divided into tandem ORFs. An additional N-terminal 3 -phosphoesterase (PE) domain (IPR014144 from INTERPRO) is present in some members of this ligase. Most examples of genes for this ligase are adjacent to the gene for Ku..

>TIGR02779 NHEJ_ligase_lig DNA polymerase LigD, ligase domain; InterPro: IPR014146 DNA repair of double-stranded breaks by non-homologous end joining (NHEJ) is accomplished by a two-protein system that is present in a minority of prokaryotes

One component is the Ku protein (see IPR009187 from INTERPRO), which binds DNA ends. The other is a DNA ligase, a protein that is a multidomain polypeptide in most of those bacteria that have NHEJ, a permuted polypeptide in Mycobacterium tuberculosis and a few other species, and the product of tandem genes in some other bacteria. This region represents the central ligase domain..

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriophages, eukarya, archaea and bacteria. This group is composed of uncharacterized fungal proteins with similarity to ATP-dependent DNA ligases. ATP dependent DNA ligases have a highly modular architecture consisting of a unique arrangement of two or more discrete domains including a DNA-binding domain, an adenylation (nucleotidyltransferase (NTase)) domain, and an oligonucleotide/oligosaccharide binding (OB)-fold domain

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriohages, eukarya, archaea and bacteria. Bacterial DNA ligases are divided into two broad classes: NAD-dependent and ATP-dependent. All bacterial species have a NAD-dependent DNA ligase (LigA). Some bacterial genomes contain multiple genes for DNA ligases that are predicted to use ATP as their cofactor, including Mycobacterium tuberculosis LigB, LigC, and LigD. This group is composed of archaeal DNA ligases and bacterial proteins similar to Mycobacterium tuberculo

>cd07900 Adenylation_DNA_ligase_I_Euk The Adenylation domain of eukaryotic DNA Ligase I is a component of the catalytic core unit

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriohages, eukarya, archaea and bacteria. Some organisms express a variety of different ligases which appear to be targeted to a specific function. There are three classes of ATP-dependent DNA ligases in eukaryotic cells (I, III and IV). DNA ligase I is required for the ligation of Okazaki fragments during lagging-strand DNA synthesis and for base excision repair (BER). DNA ligases have a highly modular architecture consisting of a unique arrangement of two or more discrete domains. The ad

>cd07902 Adenylation_DNA_ligase_III The Adenylation domain of DNA Ligase III is a component of the catalytic core unit

ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation using nicked nucleic acid substrates with the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. DNA ligases play a vital role in the diverse processes of DNA replication, recombination and repair. ATP-dependent ligases are present in many organisms such as viruses, bacteriohages, eukarya, archaea and bacteria. There are three classes of ATP-dependent DNA ligases in eukaryotic cells (I, III and IV). DNA ligase III is not found in lower eukaryotes and is present both in the nucleus and mitochondria. It has several isoforms; two splice forms, III-alpha and III-beta, differ in their carboxy-terminal sequences. DNA ligase III-beta is believed to play a role in homologous recombination during meiotic prophase. DNA ligase III-alpha interacts with X-ray Cross Complementing

>cd07894 Adenylation_RNA_ligase The Adenylation domain of RNA circularization protein, which catalyzes the circularization of RNA molecules in an ATP-dependent reaction, comprises the enzyme's catalytic unit

RNA circularization protein is capable of circularizing RNA molecules in an ATP-dependent reaction. RNA circularization may protect RNA from exonuclease activity. This model comprises the adenylation domain, the minimal catalytic unit that is common to all members of the ATP-dependent DNA ligase family, and the carboxy-terminal extension of RNA circularization protein that serves as a dimerization module. ATP-dependent polynucleotide ligases catalyze phosphodiester bond formation of nicked nucleic acid substrates using the high energy nucleotide of ATP as a cofactor in a three step reaction mechanism. The adenylation domain binds ATP and contains many active site residues.

comEA and comEC are required for transformability, whereas the products of comEB and of the overlapping comER, which is transcribed in the reverse direction, are dispensable . ComEA has been shown to be an integral membrane protein, as predicted from hydropathy analysis, with its C-terminal domain outside the cytoplasmic membrane. This C-terminal domain possesses a sequence with similarity to those of several proteins known to be involved in nucleic acid transactions including UvrC and a human protein that binds to the replication origin of the Human herpesvirus 4 (Epstein-Barr virus) ..

X family polymerases fill in short gaps during DNA repair. They are relatively inaccurate enzymes and play roles in base excision repair, in non-homologous end joining (NHEJ) which acts mainly to repair damage due to ionizing radiation, and in V(D)J recombination. This family includes eukaryotic Pol beta, Pol lambda, Pol mu, and terminal deoxyribonucleotidyl transferase (TdT). Pol beta and Pol lambda are primarily DNA template-dependent polymerases. TdT is a DNA template-independent polymerase. Pol mu has both template dependent and template independent activities. This subgroup belongs to the Pol beta-like NT superfamily. In the majority of enzymes in this superfamily, two carboxylates, Dx[D/E], together with a third more distal carboxylate, coordinate two divalent metal cations involved in a two-metal ion mechanism of nucleotide addition. These three carboxylate residues are fairly well conserved in this

It is active during DNA replication, DNA repair and DNA recombination. There are two forms of DNA ligase, one requires ATP (6.5.1.1 from EC), the other NAD (6.5.1.2 from EC), the latter being restricted to eubacteria. Eukaryotic, archaebacterial, viral and some eubacterial DNA ligases are ATP-dependent. The first step in the ligation reaction is the formation of a covalent enzyme-AMP complex. The co-factor ATP is cleaved to pyrophosphate and AMP, with the AMP being covalently joined to a highly conserved lysine residue in the active site of the ligase. The activated AMP residue is then transferred to the 5'phosphate of the nick, before the nick is sealed by phosphodiester-bond formation and AMP elimination ,. Vertebrate cells encode three well-characterised DNA ligases (DNA ligases I, III and IV), all of which are related in structure and sequence. With the exception of the atypically small PBCV-1 viral enzyme, two regions of primary sequence are common to all members of the family. The catalytic region comprises six conserved sequence motifs (I, III, IIIa, IV, V-VI), motif I includes the lysine residue that is adenylated in the first step of the ligation reaction. The function of the second, less well-conserved region is unknown. When folded, each protein comprises of two distinct sub-domains: a large amino-terminal sub-domain ('domain 1') and a smaller carboxy-terminal sub-domain ('domain 2'). The ATP-binding site of the enzyme lies in the cleft between the two sub-domains. Domain 1 consists of two antiparallel beta sheets flanked by alpha helices, whereas domain 2 consists of a five-stranded beta barrel and a single alpha helix, which form the oligonucleotide-binding fold , . ; GO: 0003910 DNA ligase (ATP) activity, 0005524 ATP binding, 0006260 DNA replication, 0006281 DNA repair, 0006310 DNA recombination.

DNA ligases catalyse the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilising either ATP or NAD(+) as a cofactor. This family is a small zinc binding motif that is presumably DNA binding. IT is found only in NAD dependent DNA ligases.

The tetrameric DNA helicase RuvA specifically binds to the Holliday junction and facilitates the isomerization of the junction from the stacked folded configuration to the square-planar structure . In the RuvA tetramer, each subunit consists of three domains, I, II and III, where I and II form the major core that is responsible for Holliday junction binding and base pair rearrangements of Holliday junction executed at the crossover point, whereas domain III regulates branch migration through direct contact with RuvB.; GO: 0003678 DNA helicase activity, 0006281 DNA repair, 0006310 DNA recombination.

It is active during DNA replication, DNA repair and DNA recombination. There are two forms of DNA ligase: one requires ATP (6.5.1.1 from EC), the other NAD (6.5.1.2 from EC). This family is predominantly composed of NAD-dependent bacterial DNA ligases. They are proteins of about 75 to 85 Kd whose sequence is well conserved , . They also show similarity to yicF, an Escherichia coli hypothetical protein of 63 Kd.; GO: 0003911 DNA ligase (NAD+) activity, 0006260 DNA replication, 0006281 DNA repair.

Accurate replication is thus one of the most important events in the cell life cycle. This function is mediated by DNA-directed DNA polymerases, which add nucleotide triphosphate (dNTP) residues to the 5'-end of the growing DNA chain, using a complementary DNA as template. Small RNA molecules are generally used as primers for chain elongation, although terminal proteins may also be used. DNA-dependent DNA polymerases have been grouped into families, denoted A, B and X, on the basis of sequence similarities , . Members of family A, which includes bacterial and bacteriophage polymerases, share significant similarity to Escherichia coli polymerase I; hence family A is also known as the pol I family. The bacterial polymerases also contain an exonuclease activity, which is coded for in the N-terminal portion. Three motifs, A, B and C , are seen to be conserved across all DNA polymerases, with motifs A and C also seen in RNA polymerases. They are centred on invariant residues, and their structural significance was implied from the Klenow (E. coli) structure. Motif A contains a strictly-conserved aspartate at the junction of a beta-strand and an alpha-helix; motif B contains an alpha-helix with positive charges; and motif C has a doublet of negative charges, located in a beta-turn-beta secondary structure .; GO: 0003677 DNA binding, 0003887 DNA-directed DNA polymerase activity, 0006260 DNA replication.

Members of this family, however, are not found in a context of RecB and RecC and are longer by about 200 amino acids at the amino end. Chlamydia muridarum has both a member of this family and a RecD. .

>TIGR01083 nth endonuclease III; InterPro: IPR005759 The spectrum of DNA damage caused by reactive oxygen species includes a wide variety of modifications of purine and pyrimidine bases

Members of this family, however, are not found in a context of RecB and RecC and are longer by about 200 amino acids at the amino end. Chlamydia muridarum has both a member of this family and a RecD. .

>cd00008 53EXOc 5'-3' exonuclease; T5 type 5'-3' exonuclease domains may co-occur with DNA polymerase I (Pol I) domains, or be part of Pol I containing complexes

They digest dsDNA and ssDNA, releasing mono-,di- and tri-nucleotides, as well as oligonucleotides, and have also been reported to possess RNase H activity. Also called 5' nuclease family, involved in structure-specific cleavage of flaps formed by Pol I activity (similar to mammalian flap endonuclease I, FEN-1). A single nucleic acid strand may be threaded through the 5' nuclease enzyme before cleavage occurs. The domain binds two divalent metal ions which are necessary for activity.

X family polymerases fill in short gaps during DNA repair. They are relatively inaccurate enzymes and play roles in base excision repair, in non-homologous end joining (NHEJ) which acts mainly to repair damage due to ionizing radiation, and in V(D)J recombination. This family includes eukaryotic Pol beta, Pol lambda, Pol mu, and terminal deoxyribonucleotidyl transferase (TdT). Pol beta and Pol lambda are primarily DNA template-dependent polymerases. TdT is a DNA template-independent polymerase. Pol mu has both template dependent and template independent activities. This subgroup belongs to the Pol beta-like NT superfamily. In the majority of enzymes in this superfamily, two carboxylates, Dx[D/E], together with a third more distal carboxylate, coordinate two divalent metal cations involved in a two-metal ion mechanism of nucleotide addition. These three carboxylate residues are fairly well conserved in this

7.7.12 from EC (galT) catalyzes the transfer of an uridyldiphosphate group on galactose (or glucose) 1-phosphate. During the reaction, the uridyl moiety links to a histidine residue. In the Escherichia coli enzyme, it has been shown that two histidine residues separated by a single proline residue are essential for enzyme activity. On the basis of sequence similarities, two apparently unrelated families seem to exist. Class-I enzymes are found in eukaryotes as well as some bacteria such as E. coli or Streptomyces lividans, while class-II enzymes have been found so far only in bacteria such as Bacillus subtilis or Lactobacillus helveticus .; GO: 0008108 UDP-glucose:hexose-1-phosphate uridylyltransferase activity, 0006012 galactose metabolic process, 0005737 cytoplasm.

Homologous Structures in PDB DatabaseDetected by PSI-BLAST, RPS-BLAST and HHsearch